bigcam406

ran my Proboat Fastech nitro the last 2 nights,first night,ran good,went threw 3 tanks,and on the 3rd tank it died.finally got it in(thanks to a kayaker),found lots of water inside.outlet line was cracked at the fitting.fixed it.yesterday,i blew compressed air threw the outlet on the boat to see if it was leaking anywhere else.found that it was leaking around the cooling head.removed it,checked all the o rings,everything was where they were supposed to be.checked all lines and fittings.all good.took it out again last night,ran for approx. 3 minutes,then died.brought it in,hull full of water again.im stumped.i don't want to run it again,as the engine has already been exposed to water 2 nights in a row.threw some after run oil in cylinder and wd40 in the carb and spun it with the starter for approx. 40 seconds to get rid of the water that it ingested.anyone have any hints as to what would be causing it to leak so bad?i have another dynamite .15 marine,was thinking of swapping heads.any help would be appreciated,as the next week,weather is supposed to be perfect,and I want to put some running time on this boat before the fall.thanks.